JP7036375B2 - Filtration method and filtration cloth used for the filtration method - Google Patents

Description

The present invention relates to, for example, a filtration method for filtering a suspension containing powder or granules such as concrete, and a filter cloth used for the filtration method.

Conventionally, a sheet-shaped filter material may be used to filter a suspension containing powder or granular material such as concrete generated at a construction site or the like.

Patent Document 1 includes a filter material made of a non-woven fabric, a frame for supporting the filter material, a filter tank for installing the filter material and the frame, and a submersible pump for transporting the suspension to the filter tank. The device is disclosed. In the filtration device of Patent Document 1, the submersible pump is installed in a storage tank in which the suspension is stored, and the suspension is pumped from the storage tank. The pumped suspension is poured into the filter medium from above the filter tank. The suspension poured into the filter material is separated into solid content and water content, the solid content is deposited on the filter material, and the water content is accumulated in the filter tank.

Patent Document 1 discloses that a coarse fiber structure is joined to the upstream side of a filter material to form a composite laminate, and clogging is alleviated by using the filter material as the composite laminate. It is said that the filtration rate can be maintained for a long period of time.

Japanese Unexamined Patent Publication No. 2002-28416

However, in the above-mentioned conventional filtration device, although the filtration performance can be maintained by devising the structure of the filtration material, if the filtration material becomes clogged, it is necessary to replace the entire filtration material immediately. It costs money. As described above, in the above-mentioned conventional filtration device, attention has not been paid to maintaining the filtration performance while reducing the cost required for replacing the filtration material, and there is room for improvement.

The room for such improvement is not limited to filtering powders such as cement, but also when filtering soil deposited in rivers and lakes, sludge in wastewater, and other suspensions. exist.

Therefore, in view of such circumstances, it is an object of the present invention to provide a filtration method which is cost-effective and can maintain the filtration performance, and a filtration cloth used for the filtration method.

The filtration method according to the present invention is a filtration method in which a plurality of filter cloths are provided, and the suspension is poured from the upper layer side in the stacking direction into a laminate in which the plurality of filter cloths are stacked to filter the suspension. ,
The first filtration step of pouring the suspension from one surface of the upper filtration cloth located on the uppermost layer of the laminate toward the upstream side toward the lower layer and filtering the suspension.
After the first filtration step, a removal step of removing the upper filter cloth from the laminate, and
It includes an additional step of adding a new filter cloth to the bottom layer of the laminate after the removal step.

According to such a configuration, the suspension is poured from one surface of the upper filtration cloth located on the uppermost layer of the plurality of laminated filter cloths toward the lower layer and filtered, and then the upper filtration used for the filtration is performed. The cloth is removed and a new filter cloth is added to the bottom layer of the laminate from which the filter cloth has been removed. As described above, in the above-mentioned method, a part of the filter cloths constituting the laminated body is replaced with a new filter cloth, so that the filtration performance can be maintained.

In this case, after performing the first filtration step, the inversion step of inverting the upper filtration cloth and after the inversion step, the suspension is poured from the other surface of the upper filtration cloth toward the lower layer and filtered. The second filtration step may be provided, and the removal step and the additional step may be performed after the second filtration step.

According to this configuration, the upper filter cloth can be inverted and the suspension can be further poured from the other side toward the lower layer for filtration, so that the suspension is filtered using both sides of the upper filter cloth. be able to. Here, when the upper filter cloth is inverted, even if the solid content accumulated on one surface of the upper filter cloth is peeled off and dropped, the solid content is placed on the filter cloth located in the lower layer than the upper filter cloth. drop down. As described above, since the suspension can be filtered using both sides of one filter cloth and the solid content can be reliably received, it is advantageous in terms of cost and it becomes easy to maintain the filtration performance.

As one aspect of the present invention, the first filtration step may be performed multiple times.

According to such a configuration, one surface of the upper filtration cloth can be used for a plurality of times of filtration.

As another aspect of the present invention, the second filtration step may be performed multiple times.

According to such a configuration, the other surface of the upper filter cloth can be used for a plurality of times of filtration.

As another aspect of the present invention, the additional step is a step in which the filter cloth on the upper layer side of the new filter cloth moves to the upper layer one by one when the new filter cloth is added.
The additional step may be carried out a plurality of times to move each filter cloth from the bottom layer to the top layer with one side facing the upstream side.

According to such a configuration, the filter cloth added to the bottom layer of the laminated body moves to the upper layer one by one with one side facing up, and finally moves to the uppermost layer. Here, in the filtration with such a laminated body, the suspension is filtered in order from the filter cloth located on the upper layer side, so that the filter cloth located on the lower layer side is the filter cloth located on the upper layer side. A solid content smaller than the solid content deposited in is deposited. Therefore, on one surface of the filter cloth added to the lowermost layer, a solid-based sedimentary layer is formed in which a smaller solid content is deposited on the lower layer side and a larger solid content is deposited on the upper layer side while moving to the upper layer one by one. To. Therefore, the filtration cloth on the upper layer side can improve the filtration performance by the deposited layer.

The filtration cloth according to the present invention is the filtration cloth used in the above-mentioned filtration method, and is attached to a sheet-shaped filtration part for filtering a suspension and a filtration part, and is predetermined in a state where the filtration part is expanded. It is provided with a fixing portion for fixing to a fixing object.

According to such a configuration, the filter cloth can be installed on the fixed object only by fixing the fixed portion to the fixed object with the filter portion expanded, so that the filter cloth can be easily installed.

From the above, according to the present invention, it is possible to provide a filtration method which is cost-effective and can maintain the filtration performance, and a filtration cloth used for the filtration method.

It is a front view of the filtration cloth used for the filtration method which concerns on this embodiment. It is a back view of the filtration cloth used for the filtration method which concerns on the same embodiment. It is a top view of the filtration cloth used for the filtration method which concerns on the same embodiment. It is a right side view of the filtration cloth used for the filtration method which concerns on the same embodiment. In FIG. 5, (a) is an enlarged view of the front side of the corner portion, and (b) is an enlarged view of the back side of the corner portion. It is sectional drawing of the filter cloth which concerns on the same embodiment, and is sectional drawing at the position of VI-VI line in FIG. 5 (b). In FIG. 7, (a) is an enlarged view of the front side of the straight line portion, and (b) is an enlarged view of the back side of the straight line portion. It is sectional drawing of the filter cloth which concerns on the same embodiment, and is sectional drawing at the position of line VIII-VIII in FIG. 7 (b). It is a figure for demonstrating the use state of the filtration method which concerns on the same embodiment. It is a figure for demonstrating the reversal process of the filter cloth which concerns on the same embodiment. It is a figure for demonstrating the state before and after reversing the upper filter cloth which concerns on the same embodiment, (a) is the figure of the state which solid content is accumulated on one surface of the upper filter cloth, (b). ) Is a diagram showing how the upper filter cloth is inverted and the solid content falls from one surface. 11 is a photograph obtained by magnifying the surface state of the filter cloth 100 times, in which (a) is the state of one surface of the upper filter cloth before inversion, and (b) is the solid dropped from the upper filter cloth. The surface state of the second layer of the filter cloth after receiving the minute, (c), is the state of one surface of the upper filter cloth after inversion. It is a figure for demonstrating the additional process of the filter cloth which concerns on the same embodiment. It is a photograph and a figure for explaining the accumulation state of solid matter in each layer in a laminated body, the left side is a photograph which magnified 1000 times the surface state of a filter cloth, and the right side is the side of the part shown in the photograph. It is a side cross-sectional view which represented the cross section in a manner. (A) is a filter cloth located in the first layer, (b) is a filter cloth located in the second layer, and (c) is a filter cloth located in the third layer. It is a photograph and a figure for explaining the accumulation state of solid matter in each layer in a laminated body, the left side is a photograph which magnified 1000 times the surface state of a filter cloth, and the right side is the side of the part shown in the photograph. It is a side cross-sectional view which represented the cross section in a manner. (A) is a filter cloth located in the fourth layer, (b) is a filter cloth located in the fifth layer, and (c) is a filter cloth located in the sixth layer. It is a figure for demonstrating the state of the solid | accumulation on the new filter cloth added to the bottom layer of a laminated body, (a) is the state located in the bottom layer, (b) is the 5th layer. (C) is the state where it is located in the fourth layer, (d) is the state where it is located in the third layer, (e) is the state where it is located in the second layer, and (f) is the most. It is the figure of the state which is located in the upper layer. It is a graph of the result of confirming whether the filtration performance is improved by the number of layers, and is the graph of the result of filtering a suspension prepared by mixing a mortar, a colorant, a water reducing agent and water. It is a graph of the result of confirming whether the filtration performance is improved by the number of layers, and is the graph of the result of filtering a suspension prepared by mixing mortar and water. It is explanatory drawing of the filter cloth which concerns on other embodiment of this invention, (a) is the explanatory view of the filter cloth which fixed part was attached only to the corner part, (b) is attached only to the straight part. It is explanatory drawing of the filtered cloth.

Hereinafter, the filtration method according to the embodiment of the present invention will be described with reference to the drawings.

For example, the washed water obtained by cleaning the inside of a pump or a pipe of a concrete pump truck that has finished discharging concrete contains particles such as concrete and is suspended. The filtration method according to the present embodiment is used to filter the suspension S as washed water to separate the concrete component (solid content S1) and the water content S2 (see FIG. 9). The filtration method of this embodiment is carried out using, for example, a filtration cloth 1 as shown in FIGS. 1 to 8. Specifically, the filtration method of the present embodiment uses a laminated body 10 (see FIG. 10) in which a plurality of filtration cloths 1 as shown in FIGS. 1 to 8 are provided and the plurality of filtration cloths 1 are laminated. Will be implemented. Therefore, first, the configuration of the filter cloth 1 will be described.

In this embodiment, the plan view of the filter cloth 1 (the view of the filter cloth 1 of FIG. 1 viewed from above) is shown in FIG. 3, but the bottom view of the filter cloth 1 (the filter cloth of FIG. 1) is shown. 1 is viewed from below) has a shape that is vertically symmetrical with the filter cloth 1 shown in FIG.

Further, in the present embodiment, the right side view of the filter cloth 1 (the view of the filter cloth 1 in FIG. 1 viewed from the right side) is shown in FIG. 4, but the left side view of the filter cloth 1 (FIG. 1). The filter cloth 1 viewed from the left side) has a shape symmetrical to that of the filter cloth 1 shown in FIG.

As shown in FIGS. 1, 2, and 9, the filtration cloth 1 is attached to a sheet-shaped filtration unit 2 for filtering the suspension S and the filtration unit 2, and the filtration unit 2 is spread out. A fixing portion 3 for fixing to a predetermined fixing object T (see FIG. 9) and a connecting means 4 (see FIG. 2) for connecting the fixing portion 3 to the filtration portion 2 are provided. The fixed object T will be described later.

As shown in FIG. 2, the filtration unit 2 includes an annular edge portion 21 formed along an edge 20 that defines the outer peripheral shape of the filtration unit 2, and the edge portion in the plane direction of the filtration unit 2. A main body portion 22 located inside the 21 is provided. The filtration unit 2 of the present embodiment is formed in a rectangular shape. Specifically, the filtration unit 2 is formed in a rectangular shape. Hereinafter, the direction in which the long side of the filtration unit 2 extends is referred to as the horizontal direction, and the direction in which the short side extends is referred to as the vertical direction. Further, the direction in which the filter cloth 1 is laminated is defined as the stacking direction. The filtration unit 2 may be formed so that the long side is 176 cm and the short side is 130 cm, for example.

The filtration unit 2 is made of a resin material. The filtration unit 2 is a woven fabric woven with resin fibers. The filtration unit 2 is a plain weave woven fabric. Therefore, as shown in FIG. 12 (c), the horizontal fibers 25 extending in the horizontal direction and the vertical fibers 24 extending in the vertical direction appear alternately on the surface of the filtration unit 2. As the material of the filtration unit 2 of the present embodiment, a resin material such as polypropylene, polyethylene, polyester or nylon can be adopted, but polyester or nylon is preferable from the viewpoint of filtration performance. Further, from the viewpoint of reducing the cost, the material of the filtration unit 2 is more preferably polyester.

As shown in FIG. 1, the end edge portion 21 includes a lateral end edge portion 21a extending in the lateral direction and a vertical end edge portion 21b extending in the vertical direction. The edge portion 21 of the present embodiment is formed by superimposing sheet members. That is, the edge portion 21 has a multi-layer structure. As shown in FIG. 8, the edge portion 21 is formed on the first strip-shaped portion 211 continuous with the main body portion 22, the second strip-shaped portion 212 superimposed on the first strip-shaped portion 211, and the second strip-shaped portion 212. A third band-shaped portion 213 that is overlapped is provided, and three sheet members are formed by being overlapped with each other.

The edge portion 21 is formed by folding back the edge 20 portion of the filtration section 2 inward. In the present embodiment, the edge portion 21 is formed by a plurality of edges 20 portions of the filtration section 2 being folded back from one surface 11 of both surfaces toward the other surface 12. The edge portion 21 of the present embodiment is formed by folding back the filtration portion 2 in the same direction. Specifically, when the filtration unit 2 is folded back twice in the same direction, the edge 20 enters the center side of the folding. A portion 213 and a first strip-shaped portion 211 are formed. That is, the second band-shaped portion 212 is formed by folding back the filtration section 2 once, and the filtering section 2 is further folded back so as to wrap the second band-shaped portion 212 inward so as to overlap the second band-shaped portion 212. The third band-shaped portion 213 and the first band-shaped portion 211 are formed.

The first strip 211, the second strip 212, and the third strip 213 are sewn by the sewing thread L and are restrained from each other. The first strip-shaped portion 211, the second strip-shaped portion 212, and the third strip-shaped portion 213 are sewn in the vicinity of the main body portion 22 side in an overlapped state.

The main body 22 is a sheet-shaped member. That is, the main body 22 has a single-layer structure. As described above, the filtration unit 2 has a multi-layer structure at the edge portion 21 and a single-layer structure at the main body portion 22.

As shown in FIG. 2, the fixing portion 3 is formed to be long. Further, the fixing portion 3 is configured by superimposing flat strings. As shown in FIGS. 6 and 8, the fixing portion 3 of the present embodiment has a folded-back portion 30 at the central portion in the longitudinal direction, and has a shape in which one string is folded back. A plurality of fixing portions 3 are attached to the filtering portion 2. In the present embodiment, the fixing portion 3 is attached to the corner portion 200 and the straight portion 201 of the filtering portion 2. The fixing portion 3 attached to the straight line portion 201 is attached to the central portion of the straight line portion 201. Eight fixing portions 3 of this embodiment are attached. FIG. 2 is a view of the filter cloth 1 as viewed from the other surface 12 side. The fixing portion 3 is attached to the other surface 12 side of the filtering portion 2.

One end of the fixing portion 3 in the longitudinal direction is attached to the filtering portion 2, and the other end is in a free state. The fixing portion 3 is attached to the filtering portion 2 with the folded portion 30 as one end side, and the pair of folded strings can be separated from each other on the other end side. The pair of strings are tied to a predetermined position of the fixed object T. In the present embodiment, the fixing portion 3 is attached to the edge portion 21 of the filtering portion 2.

The connecting means 4 is a means for connecting the fixing portion 3 to the filtering portion 2. As shown in FIGS. 5 to 8, the connecting means 4 of the present embodiment is a sewing thread and forms a seam portion 40. Specifically, the fixing portion 3 is sewn to the filtering portion 2 using a sewing thread.

The seam portion 40 is formed so as to intersect the fixed portion 3 in the longitudinal direction. The seam portion 40 has a pair of first seam portions 41 separated from each other in the longitudinal direction of the fixing portion 3, and a second seam portion 42 formed so as to connect the pair of first seam portions 41. .. The pair of first stitch portions 41 extend in a direction substantially orthogonal to the longitudinal direction of the fixing portion 3. The second seam portion 42 extends so as to connect one end of one of the first seam portions 41 of the pair of first seam portions 41 and the other end of the other first seam portion 41. .. That is, the seam portion 40 of the present embodiment is formed in a Z shape.

Hereinafter, the mounting state of the filtration unit 2 and the fixing unit 3 will be described.

FIG. 5 (a) is an enlarged view of the corner portion 200 of the filtration unit 2 as viewed from one surface 11 side of the filtration unit 2, and FIG. 5 (b) shows the corner portion 200 of the filtration unit 2 as the filtration unit 2. It is an enlarged view seen from the other side surface 12 side of. The fixing portion 3 is attached at a position where the horizontal end edge portion 21a and the vertical end edge portion 21b overlap each other. As shown in FIG. 6, the edge portion 21 of the filtration unit 2 is formed by folding back the vertically extending edge 20 portion while the laterally extending edge 20 portion is folded back, for example. .. That is, in the corner portion 200, the horizontal end edge portion 21a is folded back twice as a part of the vertical end edge portion 21b. Therefore, since each of the band-shaped portions 211, the second strip-shaped portion 212, and the third strip-shaped portion 213 of the vertical end edge portion 21b has a three-layer structure and overlaps with each other, the sheet member ( The filtration unit 2) has a multi-layer structure in which 9 layers are stacked.

The fixing portion 3 is connected to an overlapping portion 210 in which the horizontal end edge portion 21a and the vertical end edge portion 21b overlap. The fixing portion 3 is connected to the overlapping portion 210 by a sewing thread. By connecting the fixing portion 3 to the overlapping portion 210 having a multilayer structure, the strength of the connecting portion between the filtering portion 2 and the fixing portion 3 can be increased. Specifically, the filtering portion 2 and the fixing portion 3 are formed by the sewing thread penetrating the 11-layer multilayer body W composed of the overlapping portion 210 having a 9-layer structure and the pair of strings overlapped with the overlapping portion 210. Is connected. Further, since the pair of first seams 41 of the seams 40 extend in a direction substantially orthogonal to the longitudinal direction of the fixing portions 3, the strength in the longitudinal direction in which the fixing portions 3 are pulled increases, and the filtering portion The connection strength between 2 and the fixed portion 3 is secured.

FIG. 7A is an enlarged view of the straight section 201 of the filtration section 2 as viewed from one surface 11 side of the filtration section 2, and FIG. 7B is an enlarged view of the straight section 201 of the filtration section 2 as viewed from the filtration section 2. It is an enlarged view seen from the other side surface 12 side of. In the straight line portion 201, the fixing portion 3 is attached to the edge portion 21. FIG. 7 (b) shows a state in which the fixing portion 3 is attached to the horizontal end edge portion 21a, but the state in which the fixing portion 3 is attached to the vertical end edge portion 21b is the same as in FIG. 7 (b). be. As shown in FIG. 8, in the straight line portion 201, the sewing thread penetrates the five-layered multilayer body W composed of a pair of strings overlapped with the horizontal end edge portion 21a of the three-layer structure, so that the filtering portion 2 is used. And the fixed portion 3 are connected.

This concludes the description of the filter cloth 1. Hereinafter, a method of using the filtration method according to the present embodiment will be described with reference to the drawings.

As shown in FIG. 9, the filtration method of the present embodiment is a filtration method in which the suspension S is poured from the upper layer side in the stacking direction into the laminate 10 on which a plurality of filtration cloths 1 are stacked, and the suspension S is filtered. Is. The filtration method includes a first filtration step of pouring the suspension S from one surface 11 of the upper filtration cloth 1a located on the uppermost layer of the laminate 10 toward the upstream side in the filtration direction toward the lower layer and filtering. After the first filtration step, the inversion step of inverting the upper filtration cloth 1a, and after the inversion step, the suspension S is poured from the other surface 12 of the upper filtration cloth 1a toward the lower layer and filtered. 2 Filtration step, after the second filtration step, a removal step of removing the upper filtration cloth 1a from the laminate 10, and an additional step of adding a new filtration cloth 1 to the bottom layer of the laminate 10 after the removal step. And. In the present embodiment, the first filtration step is to carry out filtration a plurality of times. Further, in the second filtration step, filtration is performed a plurality of times. Hereinafter, each step will be specifically described.

In the present embodiment, the subject who uses (implements) the filtration method will be described as an operator, but the subject who uses the filtration method may be, for example, a device such as a robot.

The operator installs the laminated body 10 on the object T to be fixed in a state where the central portion of each filter cloth 1 is recessed in a concave shape. The predetermined fixed object T of the present embodiment is, for example, a basket-shaped member having an opening formed on the lower side so that the moisture S2 filtered by the filter cloth 1 can pass through. The operator connects the fixing portion 3 attached to each filtration cloth 1 of the laminated body 10 to the frame of the fixed object T or the like, and fixes the laminated body 10 to the fixed object T. A water receiving portion P for receiving the moisture S2 obtained by filtration may be provided on the lower side of the fixed object T.

In the first filtration step, the operator pours the suspension S from above the laminated body 10 toward the lower layer from one surface 11 of the upper filtration cloth 1a located on the uppermost layer of the laminated body 10. The suspension S may be washed water obtained by washing a concrete pump truck or the like, and may be washed water in an unfiltered state or may be washed water that has been primary filtered by another filtering means. Further, the pouring means for pouring the suspension S into the laminate 10 may be, for example, a transportation means installed on the upstream side of the laminate 10, or the operator may pour the suspension S stored in a bucket or the like. It may be a manual means to put it in. Further, the pouring means may be a means for directly dropping the suspension S exuded from another filtering means onto the laminate 10, and the pouring means is not particularly limited. ^ The suspension S is separated into a solid content S1 and a water content S2 in the first filtration step. The separated solid content S1 is deposited on the filter cloth 1, and the water content S2 that has passed through the filter cloth 1 is accumulated in the water receiving portion P.

In the present embodiment, for example, the state in which the entire amount of the suspension S requiring filtration is filtered at the filtration site is regarded as the state in which the first filtration step is performed once. Alternatively, a state in which a predetermined amount of suspension S determined based on various conditions such as the size and performance of the filter cloth 1 is filtered is defined as a state in which the first filtration step is performed once. In the first filtration step, filtration is performed a plurality of times until one surface 11 is substantially covered with the solid content S1. In the first filtration step, for example, filtration is performed three times.

As shown in FIG. 10, in the reversing step, the operator removes the upper filter cloth 1a from the fixing object T and turns the front and back sides upside down. Although the laminated body 10 is represented flat in FIG. 10, the upper filter cloth 1a may be inverted while the laminated body 10 is fixed to the object T to be fixed. After reversing the upper filter cloth 1a, the operator connects the fixing portion 3 to the fixing object T and fixes it.

11 and 12 show the state before and after reversing the upper filter cloth 1a. As shown in the figure of FIG. 11A and the photograph of FIG. 12A, the solid content S1 is deposited on one surface 11 of the upper filtration cloth 1a before the inversion step to have a predetermined thickness. When the upper filter cloth 1a is inverted in the inversion step, the block-shaped solid content S1 becomes a mass and becomes the lower filter cloth 1 as shown in the figure of FIG. 11 (b) and the photograph of FIG. 12 (b). Fall. FIG. 12B is the surface of the filter cloth 1 located on the lower layer side of the upper filter cloth 1a after the inversion step. From FIG. 12B, it can be seen that the solid content S1 dropped from the upper filter cloth 1a is formed into a block-shaped mass and is received by the filter cloth 1 located on the lower layer side. Note that FIG. 12 (c) is a photograph of one surface 11 of the upper filter cloth 1a immediately after inversion, and most of the solid content S1 deposited on the upper filter cloth 1a is inverted so that the one surface 11 is formed. It can be seen that it peels off from and falls.

As described above, the solid content S1 that falls from the upper filter cloth 1a by the inversion step falls as a block-shaped mass, so that the solid content S1 does not easily enter the eyes of the filter cloth 1 located on the lower layer side, and continues. In the second filtration step, the clogging of the filter cloth 1 located on the lower layer side can be delayed, and the laminated body 10 as a whole can be made to last for a long time.

In the second filtration step, the operator pours the suspension S from above the laminate 10 toward the lower layer from the other surface 12 of the upper filtration cloth 1a located on the uppermost layer of the laminate 10. The state of the suspension S and the pouring means are the same as in the first filtration step. Further, in the second filtration step, filtration is performed a plurality of times until the other surface 12 is substantially covered with the solid content S1. In the second filtration step, for example, filtration is performed three times.

In the second filtration step, one surface 11 of the upper filtration cloth 1a is backwashed by pouring the suspension S from the other surface 12 of the upper filtration cloth 1a. Therefore, when the upper filter cloth 1a is reused after the upper filter cloth 1a is removed, it is possible to save the washing water related to the washing of the upper filter cloth 1a and reduce the work load related to the washing. be able to.

In the removing step, the operator removes the upper filter cloth 1a from the fixed object T and removes the upper filter cloth 1a from the fixed object T. Then, the operator adds a new filtration cloth 1 to the bottom layer of the laminated body 10 after the removal step. FIG. 13 is a view after the upper filter cloth 1a is removed, and shows a state in which a new filter cloth 1 is added to the laminated body 10 in a state where five filter cloths 1 remain. The new filter cloth 1 is added to the lower layer side of the lower filter cloth 1b located at the lowest layer in the stacking direction. Although the laminated body 10 is represented flat in FIG. 13, a new filtering cloth 1 may be laid under the lower filtering cloth 1b in a state where the laminated body 10 is fixed to the object T to be fixed.

After the addition step, the first filtration step is carried out in order, and when the addition step is completed again, the first filtration step is further carried out. As described above, in the filtration method of the present embodiment, by repeating the first filtration step to the additional step, it is possible to continuously filter while maintaining the filtration performance while partially exchanging the laminated body 10. ..

Here, FIGS. 14 (a) to 14 (c) and FIGS. 15 regarding the state of accumulation of the solid content S1 on each of the filtration cloths 1 from the uppermost layer (first layer) to the lowermost layer (sixth layer) of the laminated body 10. This will be described with reference to (a) to (c). In order to observe the accumulation state of the solid content S1 on each filter cloth 1, water was added to the mixture of the mortar and the water reducing agent to prepare a suspension S, which was poured into the laminate 10. A mixture was prepared by mixing 1% of the water reducing agent with the mortar, and water was added to the mixture so that the volume ratio was water / mixture = 49 to prepare a suspension S.

Six filter cloths 1 were superposed, and the suspension S was poured from one surface 11 of the upper filter cloth 1a located on the uppermost layer toward the lower layer to perform filtration. After the solid content S1 deposited on each filter cloth 1 was dried, the accumulated state of each filter cloth 1 was observed. FIG. 14A shows the surface of the filter cloth 1 located in the uppermost layer (first layer), and FIG. 14B and thereafter show the surface of the filter cloth 1 in order from the second layer. FIG. 15C is the surface of the lower filter cloth 1b located in the lowermost layer (sixth layer). From FIGS. 14 (a) to 14 (c) and FIGS. 15 (a) to 15 (c), the amount of solid content S1 deposited decreases in order from the uppermost layer, and the particle size of solid content S1 decreases. You can see that.

In the filtration method of the present embodiment, the additional step is a step in which the filter cloth 1 on the upper layer side of the new filter cloth 1 moves to the upper layer one by one when the new filter cloth 1 is added. The process is carried out a plurality of times to move each filter cloth 1 from the bottom layer to the top layer with one surface 11 facing the upstream side. The surface state of one surface 11 of the lower filter cloth 1b when the additional step is carried out a plurality of times, for example, when the lower filter cloth 1b located in the lowermost layer moves to the upper layer one layer at a time will be described.

The surface state of the lower filter cloth 1b in the state where the second filtration step is completed is shown in order in FIGS. 16 (a) to 16 (f) with reference to FIGS. 14 and 15. As shown in FIGS. 16 (f) and 16 (a), in a state where the second filtration step is completed, a small amount of solid content S1 having a small particle size is deposited on the surface of the lower filtration cloth 1b. When a new filter cloth 1 is added to the lowermost layer of the laminate 10, that is, the lower side of the lower filter cloth 1b by the additional step, the lower filter cloth 1b is located at the fifth layer counting from the uppermost layer. Will be done. The lower filter cloth 1b is no longer located in the lowermost layer, but for the sake of explanation, it is referred to as the lower filter cloth 1b until it is located in the uppermost layer.

The first filtration step, the inversion step, and the second filtration step are performed again with the lower filter cloth 1b located in the fifth layer, so that the surface of the lower filter cloth 1b located in the fifth layer is shown in the figure. As shown in 16 (b), in addition to the solid content S1 deposited when it was located in the lowest layer, the solid content S1 having a particle size larger than that of the solid content S1 is deposited (solid content in FIG. 15 (b)). Equivalent to minute S1). Therefore, a larger amount of solid content S1 is deposited on the lower filter cloth 1b that has moved from the bottom layer to the fifth layer, and the particle size of the solid content S1 is from the lower side. The particle size increases toward the upper side.

When the removal step and the additional step are carried out, the lower filter cloth 1b moves from the 5th layer to the 4th layer. The first filtration step, the inversion step, and the second filtration step are performed again with the lower filter cloth 1b located in the fourth layer, so that the surface of the lower filter cloth 1b located in the fourth layer is shown in the figure. As shown in 16 (c), in addition to the solid content S1 deposited when it was located at the bottom layer and the fifth layer, the solid content S1 having a particle size larger than that of the solid content S1 is deposited (FIG. 15 (FIG. 15). a) Corresponds to the solid content S1). As described above, as the lower filtration cloth 1b moves to the upper layer layer by layer, the solid content S1 having a large particle size is sequentially deposited on the solid content S1 having a small particle size, and the solid content S1 having a large particle size is repeatedly deposited in the uppermost layer. In this state, the solid content S1 is laminated as shown in FIG. 16 (f).

When the first filtration step is performed in a state where the lower filter cloth 1b moves to the uppermost layer and becomes the upper filter cloth 1a, the laminated body 10 uses the filter cloth 1 in the state of FIG. 16 (f) as the uppermost layer. As the upper filter cloth 1a, the second layer is the filter cloth 1 in the state of FIG. 16 (e), the third layer is the filter cloth 1 in the state of FIG. 16 (d), and the fourth layer is the state of FIG. 16 (c). The filter cloth 1 in the state of FIG. 16 (b) is laminated on the first and fifth layers of the filter cloth 1, and the filter cloth 1 in the state of FIG. 16 (a) is laminated on the bottom layer (sixth layer). ..

In such a laminated body 10, when the lower filter cloth 1b moves to the uppermost layer and becomes the upper filter cloth 1a, the sedimentary layer of the solid content S1 on the upper filter cloth 1a has a large particle size from the bottom to the top. When the first filtration step is started, the large solid content S1 is captured on the upper side of the sedimentary layer and the small solid content S1 is captured on the lower side of the sedimentary layer. Therefore, the ability of each filter cloth 1 to capture the solid content S1 improves as it moves toward the upper layer side.

As described above, the filtration method of the above embodiment includes a first filtration step, a removal step, and an additional step. The upper filter cloth 1a used for filtration is removed, and a new filter cloth 1 is added to the bottom layer of the laminate 10 from which the upper filter cloth 1a has been removed. As described above, in the above-mentioned method, a part of the filter cloths constituting the laminated body is replaced with a new filter cloth, so that the filtration performance can be maintained.

Further, in the filtration method according to the present embodiment, since the inversion step and the second filtration step are performed after the first filtration step, the upper filter cloth located on the uppermost layer of the plurality of laminated filter cloths 1 is used. After pouring the suspension S from one surface 11 of 1a toward the lower layer and filtering, the upper filtration cloth 1a is inverted and the suspension S is further poured from the other surface 12 toward the lower layer and filtered. Therefore, the suspension S can be filtered using both sides of the upper filtration cloth 1a. Here, when the upper filter cloth 1a is inverted, even if the solid content S1 deposited on one surface 11 of the upper filter cloth 1a peels off and falls, the solid content S1 remains in the lower layer than the upper filter cloth 1a. It falls on the located filter cloth 1. In this way, the suspension S can be filtered using both sides of one filter cloth 1, and the solid content S1 can be reliably received, which is advantageous in terms of cost and maintains the filtration performance. It will be easier.

Further, according to the above embodiment, in the first filtration step, filtration is performed a plurality of times. Therefore, one surface 11 of the upper filtration cloth 1a can be used for a plurality of times of filtration.

Further, according to the above embodiment, in the second filtration step, filtration is performed a plurality of times. Therefore, the other surface 12 of the upper filtration cloth 1a can be used for a plurality of times of filtration.

Further, according to the above embodiment, the additional step is a step in which the filter cloth 1 on the upper layer side of the new filter cloth 1 moves to the upper layer one by one when the new filter cloth 1 is added. The additional step is carried out a plurality of times to move each filter cloth 1 from the bottom layer to the top layer with one surface 11 facing the upstream side.

According to such a configuration, the filter cloth 1 added to the lowermost layer of the laminated body 10 moves to the upper layer one by one with one surface 11 facing up, and finally moves to the uppermost layer. Here, in such filtration with the laminated body 10, the suspension S is filtered in order from the filter cloth 1 located on the upper layer side, so that the filter cloth 1 located on the lower layer side is placed on the upper layer side. A solid content S1 smaller than the solid content S1 deposited on the located filter cloth 1 is deposited. Therefore, on one surface 11 of the filter cloth 1 added to the lowermost layer, the solid content S1 in which the lower layer side has a smaller solid content S1 and the upper layer side has a larger solid content S1 is deposited while moving to the upper layer one by one. A sedimentary layer is formed. Therefore, the filtration cloth 1 on the upper layer side can improve the filtration performance by the deposited layer.

Further, the removal step of the above embodiment is a step of removing only the upper filter cloth 1a of the uppermost layer. That is, in the above embodiment, the filter cloth 1 is used a plurality of times while moving from the state where the filter cloth 1 is located in the lowermost layer to the upper layer, and only the oldest upper filter cloth 1a is removed. Therefore, for example, as shown in Table 1, it is possible to suppress the variation in the filtration performance before and after the removal of the upper filtration cloth 1a, and it is possible to maintain a constant filtration performance.

For example, as shown in Table 1, the degree of contamination of each filter cloth 1 in the laminate 10 after the addition of the new filter cloth 1 and before the first filtration step is carried out (“a. First filtration step” in Table 1). "Before implementation") is set to 75, 60, 45, 30, 15, 0 in order from the top layer side. After the second filtration step is carried out through the first filtration step, each filter cloth 1 is in a more dirty state than before the first filtration step is carried out. The degree of contamination of each filter cloth 1 in the laminated body 10 in this state (“b. After the second filtration step” in Table 1) is set to 90, 75, 60, 45, 30 and 15 in order from the uppermost layer side. Subsequently, the degree of contamination of each filter cloth 1 in the laminate 10 from which the upper filter cloth 1a was removed and a new filter cloth 1 was added (“c. Replacement of the upper filter cloth 1a after performing the second filtration step” in Table 1”. ), As a result of each filter cloth 1 moving to the upper layer one layer at a time, the degree of contamination becomes 75, 60, 45, 30, 15, 0 in order from the uppermost layer side, and the contamination is improved. Then, the state of the laminated body 10 after the removal of the upper filter cloth 1a and the addition of the new filter cloth 1 (the state of "c. Replacement of the upper filter cloth 1a after the implementation of the second filtration step" in Table 1) is the first filtration. It is close to the state of the laminated body 10 before the step is carried out (the state of "a. Before the first filtration step is carried out" in Table 1), and the filtration performance before and after the removal of the upper filter cloth 1a does not change significantly. However, when all the filter cloths 1 are replaced after the second filtration step (“b. After the first filter step” in Table 1), the degree of contamination of all the filter cloths 1 (“d. Second” in Table 1). "Replacement of all filtration cloths 1 after the filtration step") becomes 0, and the variation in filtration performance before and after the removal of the upper filtration cloth 1a becomes large. As described above, the filtration method according to the present embodiment also has the effect of facilitating the control of the filtration performance of the laminated body 10 and the control of the dirty state of each filtration cloth 1 by maintaining the filtration performance constant. obtain.

Further, according to the filtration cloth 1 according to the present embodiment, the sheet-shaped filtration unit 2 for filtering the suspension is fixed to the predetermined fixing object T in a state where the filtration unit 2 is expanded. Since the fixed portion 3 is attached, the filter cloth 1 can be easily installed by installing the filter cloth 1 on the fixed object T by simply fixing the fixed portion 3 to the fixed object T with the filter unit 2 expanded. can do.

Further, in the filtration cloth 1 according to the present embodiment, since the fixing portion 3 is attached to the straight portion 201 in addition to the corner portion 200 of the filtering portion 2, the fixing portion T is attached to the fixed object T in a state where the filtering portion 2 is expanded. It becomes easy to fix.

Further, in the filtration cloth 1 according to the present embodiment, since the seam portion 40 connecting the fixing portion 3 to the filtering portion 2 is formed in a Z shape, the connection strength between the fixing portion 3 and the filtering portion 2 is increased. It will increase.

It should be noted that the filtration method of the present invention is not limited to the above embodiment, and it is needless to say that various modifications can be made without departing from the gist of the present invention.

In the above embodiment, the invention has been described as the invention of the filtration method, but it can also be regarded as the invention of the filtration cloth 1 used in the filtration method. Further, it can be regarded as an invention of a laminated body 10 in which a plurality of filter cloths 1 are provided and the plurality of filter cloths 1 are laminated. Since the configurations of the filter cloth 1 and the laminate 10 are the same as the configurations of the filter cloth 1 and the laminate 10 in the above embodiment, the description thereof will not be repeated.

In the above embodiment, the case where the laminated body 10 is composed of six filter cloths 1 has been described, but the present invention is not limited thereto. The number of filter cloths 1 constituting the laminated body 10 is not limited. The laminate 10 may be composed of two or more filter cloths 1, and the filter cloth 1 may be 6 or more or 6 or less.

Here, the number of the filtering cloths 1 constituting the laminated body 10 was changed, and a confirmation test of the filtering performance was conducted to see if the filtering performance changed. The test results are shown in FIGS. 17 and 18. In the confirmation test, two types of suspensions S were prepared: a first suspension S in which mortar, a colorant, a water reducing agent and water were mixed, and a second suspension S in which mortar and water were mixed. Further, in the confirmation test, five types of laminates 10 composed of one filter cloth 1 and two to six filter cloths 1 are prepared, and a total of six types are used as filters for the first suspension on each filter. The turbid liquid S and the second suspension S were poured and filtered. The absorbance of the water content S2 obtained by filtering the filter was measured with an absorptiometer (UVmini-1240 manufactured by Shimadzu Corporation), and the relationship between the number of filters and the absorbance was graphed. The lower the absorbance, the more transparent the water S2, which means that the filtration performance is good. FIG. 17 is a graph of the result of pouring the first suspension S, and FIG. 18 is a graph of the result of pouring the second suspension S.

From FIG. 17, when the first suspension S is filtered, the absorbance suddenly increases between the laminate 10 composed of three filter cloths 1 and the laminate 10 composed of four filter cloths 1. Decreased to. That is, when filtering the first suspension S, it is preferable that the laminated body 10 is composed of four or more filtering cloths 1. Further, from FIG. 18, when filtering the second suspension S, the absorbance between the laminate 10 composed of two filter cloths 1 and the laminate 10 composed of three filter cloths 1 is observed. Decreased sharply. That is, when filtering the second suspension S, it is preferable that the laminate 10 is composed of three or more filter cloths 1. From the above, it can be seen that the laminated body 10 is preferably composed of at least three or more filter cloths 1, and more preferably composed of four or more filter cloths 1.

In the above embodiment, the case where the filtration unit 2 has a multi-layer structure formed by the edge portion 21 by being folded back has been described, but the filtration unit 2 may not be folded back. For example, the filtration unit 2 may have a multi-layer structure at the edge portion 21 by stacking a plurality of independent strip-shaped members. Further, the edge portion 21 may have a single-layer structure. In this case, the edge of the filtration unit 2 may be treated so that the fibers do not fray due to fusing.

In the above embodiment, the case where the filtration unit 2 is formed in a rectangular shape has been described, but the present invention is not limited to this. The filtration unit 2 may be formed in a square shape. Further, the filtration unit 2 may be formed in a polygonal shape such as a circular shape, an elliptical shape, or a triangular shape.

In the above embodiment, the case where the fixing portion 3 is composed of a long and flat string body has been described, but the present invention is not limited to this. The shape of the string is not limited, and the string may have a circular outer peripheral shape such as a rope. Further, the fixing portion 3 may have a structure capable of fixing the filtration cloth 1 to the fixing object T, and may be, for example, a clip.

In the above embodiment, the case where the filtration unit 2 and the fixing unit 3 are sewn using a sewing thread has been described, but the present invention is not limited to this. For example, the fixing portion 3 may be fixed to the filtering portion 2 using an adhesive such as a hot melt resin adhesive.

Further, the fixing portion 3 is filtered by forming a through hole penetrating in the thickness direction in the filtering portion 2, attaching a string body to the fixing portion 3, passing the string body through the through hole, and connecting the string body to the filtering portion 2. It may be attached to the part 2. In this case, a ring-shaped member may be attached to the inner peripheral edge of the through hole of the filtration unit 2.

In the above embodiment, the case where the fixing portion 3 is attached to the corner portion 200 and the straight portion 201 of the filtering portion 2 and a total of eight are attached is described, but the present invention is not limited thereto. The mounting position and number of the fixing portions 3 can be freely set. For example, the fixing portion 3 may be attached only to the corner portion 200 or only to the straight portion 201, and a total of six fixed portions 3 may be attached to each corner portion 200 and each long side of the straight portion 201. May be done.

The filtering cloth 1 in which the fixing portion 3 is connected only to the corner portion 200 (see FIG. 19A) and the filtering cloth 1 in which the fixing portion 3 is connected only to the straight portion 201 (FIG. 19B). If the laminated body 10 is formed by alternately stacking and laminating the laminated body 10 with respect to the fixed object T, the fixed position of the fixed portion 3 of each filter cloth 1 can be dispersed with respect to the fixed object T, so that the laminated body 10 can be fixed. It can be easily attached to T.

In the above embodiment, the inversion step and the second filtration step are performed after the first filtration step, but the configuration is not limited to this. For example, after the first filtration step, the removal step may be performed without performing the inversion step and the second filtration step.

1 ... Filtration cloth, 1a ... Upper filter cloth, 1b Lower filter cloth, 11 ... One side, 12 ... The other side, 2 ... Filtration part, 21 ... Edge part, 21a ... Horizontal edge part, 21b ... Vertical end Edge part, 22 ... Main body part, 24 ... Vertical fiber, 25 ... Horizontal fiber, 200 ... Square part, 201 ... Straight part, 211 ... First band-shaped part, 212 ... Second band-shaped part, 213 ... Third band-shaped part, 3 ... fixing part, 4 ... connecting means, 40 ... seam part, 41 ... first seam part, 42 ... second seam part, 10 ... laminated body, P ... water receiving part, S ... suspension, S1 ... Solid content, S2 ... Moisture, T ... Fixed object, W ... Multilayer

Claims (5)

It is a filtration method in which a plurality of filter cloths are provided, and the suspension is poured from the upper layer side in the stacking direction into a laminate in which the plurality of filter cloths are stacked to filter the suspension.
The first filtration step of pouring the suspension from one surface of the upper filtration cloth located on the uppermost layer of the laminate toward the upstream side toward the lower layer and filtering the suspension.
After the first filtration step, a removal step of removing the upper filter cloth from the laminate, and
A filtration method comprising an additional step of adding a new filter cloth to the bottom layer of the laminate after the removal step. After performing the first filtration step, the inversion step of inverting the upper filter cloth and the inversion step.
After the inversion step, a second filtration step of pouring the suspension from the other surface of the upper filter cloth toward the lower layer and filtering the suspension is provided.
The filtration method according to claim 1, wherein the removal step and the additional step are performed after the second filtration step. The filtration method according to claim 1 or 2, wherein the first filtration step is performed a plurality of times. The filtration method according to claim 2, wherein the second filtration step is performed a plurality of times. The additional step is a step in which the filter cloth on the upper layer side of the new filter cloth moves to the upper layer one by one when the new filter cloth is added, and the additional step is carried out a plurality of times to carry out each filter cloth. The filtration method according to any one of claims 1 to 4, wherein the cloth is moved from the bottom layer to the top layer with one surface facing the upstream side.

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